Electrical mechanism



Feb. 27', 1934. R CHILTON 1,949,367

ELECTRICAL ME CHANI SM Original Filed Odt. 18, 1929 INVENTOR. Roland Chi/fan aha g Patented'feb. 27, 1934 1,949,367 nnermost cnmsm Roland Chilton, Ridgewood, N. J., assignor in Eclipse Aviation Corporation, East Orange, N. J., a corporation of New Jersey Original application October 18, 1929, Serial No.

400,704. Divided and this application December 16, 1932. Serial No. 647,673

8 Claims.

This invention relates to electrical mechanism and particularly to dynamo electric machines of the type embodying armature and field members adapted for relative rotation.

| One of the objects of the invention is to provide a dynamo electric machine of such construction that the rotating element thereof con stitutes an inertia element in which energy may be developed for transmission to a part to be driven, as for example, an engine starting mechanism of the character indicated in the accompanying drawing, reproduced from my co-pending application Serial Number 400,704, of which application the present one is a division. The ll said co-pending application has now matured as Patent No. 1,900,799 granted March 7, 1933.

Another object of the present invention is to provide a novel dynamo electric machine of the above character in which the construction of the rotating parts, and their relation'to the nonrotating parts, is such as to produce the inertia eifect above described, while at the same time confining the machine within a minimum of space and to a minimum weight for its size.

A further object is to provide novel means for mounting the motor brushes for movement with respect to the commutator.

Oneembodiment of the invention is illustrated in the accompanying drawing, but it is to be ex- 80 pressly understood that'said drawing is for the purpose of illustration only and is not to be construed as a definitionof the limits of the invention, reference being had to the appended claims for this purpose.

In said drawing,

, Fig. 1 is an elevation, partly in section, of one embodiment of the invention; and l Fig. 2 is a detail in perspective showing the brush mounting and actuating means.

Referring now to the drawing, wherein like numerals indicate like parts throughout the several views, the starting mechanism to which the present invention is shown applied is housed in a sectional casing 4 of any suitable type, which casing is adapted to be secured by means such as bolts 5 to the casing of an internal combustion engine (not shown). Mounted in suitable bearings in the casing 4 is the shaft 6 of an electric motor, said shaft being provided with suitable teeth 7 meshing with a large pinion 8 that is drivably connected through a suitable train of reduction gearing (not shown) with a clutch jaw 9. Preferably a yielding driving connection is interposed :between the pinion a and the clutch jaw 9, said J yielding connection in the form shown comprising friction clutch means 10 of the type described In my Patent No. 1,632,539, dated June 14, 1927.

The clutch jaw 9 is adapted to be shifted axially into engagement with a member of the engine to be started by any suitable shifting mecha0 anism (not shown) actuated by a rock shaft 11. The mechanism above described is well understood in the art and constitutes no part per se of the present invention, and any known type of such mechanism can be employed which is as suitable for the purpose described.

The electric motor in which the invention herein is shown as embodied preferably comprises a stationary field structure including pole pieces 12 having field coils 13 thereon and se- (0 cured to the casing 4 in any suitable manner, as by means of screws or bolts 14. The rotating motor armature is constituted by a supporting disc 15 having a hub which is keyed at 16 to the shaft 6 and carries adjacent its periphery suit- 16 able laminations 1'1 and armature windings 18. The rotating armature thus constituted is of considerable weight and of relatively great radius and may constitute the inertia element of the starting mechanism, the energy of rotation of which is effective to rotate the clutch jaw 9 to crank the engine. The shaft 6 likewise carries a commutator 19 comprising a plurality of segments to which the armature windings 18 are suitably connected, and suitable brushes 20 are adapted 86 to engage said commutator to operate the motor. Means are provided for mounting the brushes 20 with respect to the commutator 19, whereby said brushes are resiliently maintained out of engagement with said commutator under normal conditions and may be displaced into engagement with said commutator to rotate the motor armature or inertia element. In the form shown, the commutator 19 is housed in a cup 21 that is suitably secured to the casing 4 by means of a screw or screws 22 and a ring 23 is adjustably mounted on said cup, said ring having inner and outer flanges 24 as seen in Fig. 2. The upper part of the inner flange 24 is provided with a slot 25 through which one of the screws 22 extends, whereby the ring 23 is held fixed with respect to the cup 21 and the outer housing 4. Resilient cantilever arms 26, such as leaf springs are mounted on pins 27 that extend between the inner and outer flanges 24 and each of said arms 26 carries a brush 20, the normal position of said brushes being out of contact with the commutator 19. The brushes 20 extend through registering openings 28 in the ring 23 and cup 21, and flexible leads 29 connect the brushes 20 with a terminal block 30.

In the form shown, the outer flange 24 on the ring 23 is provided with an upwardly and laterally extending portion 31 which serves as a bracket on which a bell crank lever is pivoted by means of a pivot pin 32. The horizontally extending arm 33 of the bell crank lever has an-eye 34 through which loosely extends a pin 35 carrying a bridging member or yoke 36 provided with rounded ends 37 adapted to engage and flex the resilient arms 26. The vertically extending arm 38 of the bell crank lever is connected to a link 39 which passes freely through an opening in a lug 40 formed on a swinging lever 41 that is pivoted by means of a pin 42 on the starter housing 4. Resilient means such as a coil spring 43 is interposed between the lug 40 and a plate 44 secured to the link 39. An operating or control rod 45 is connected to the upper end of the lever 41, so that when the control rod is pushed to the right, as seen in Fig. 2, the lever 41 swings about its pivot and compresses the spring 43 thereby resiliently urging link 39 to the right and rotating the bell crank lever on its pivot 32 to depress the arms 26 and the brushes 20.

Preferably the control rod 45 likewise serves to shift the clutch jaw 9 into engagement with the engine to be cranked after the inertia element has been accelerated either manually or by power. Accordingly the lever 41 is provided with a lug 46 which, when the control rod is pulled to the left as seen in Fig. 2, engages and rotates a swinging frame 47 that is preferably pivoted on the pin 42. An arm 48 on the frame 47 is connected by means of a link 49 anda rock arm 50 with the rock shaft 11 which, as above described, shifts the clutch jaw 9 axially into cranking position.

When it is desired to accelerate the starter by power, the operating rod 45 is first pushed to the right as seen in Fig. 2, whereupon the brushes 20 are depressed as above described into engagement with the commutator 19. The motor then starts and as soon as the desired speed of rotation of the armature has been reached, the control rod 45 is pulled sharply to the left to shift the clutch jaw 9, as above described and claimed in my earlier application Serial No. 400,704 above referred to, into cranking position, whereupon the spring 43 is released and the resilient arms 26 lift the brushes out of engagement with the commutator, thereby simultaneously breaking the motor circuit and removing the brush load from the commutator.

The apparatus, while simple and economical to construct, is effective and reliable in operation and is designed so as to have the least possible weight and to occupy the least possible space. The brushes and the resilient mounting therefor are bodily adjustable around the commutator axis without disturbing or interfering with the means whereby the brushes are depressed into engagement with the commutator.

While only one embodiment of the invention has been described and illustrated in the drawing, it is to be expressly understood that the invention is not limited thereto, but is capable of embodiments other than that described. For example, the invention is not limited to any particular type of electric motor or use since the invention may be applied to any use wherein it is desirable that the rotor of the machine shall constitute an inertia member in which a large amount of kinetic energy may be stored. Likewise other changes may be made in the form, construction and arrangement of the parts without departing from the spirit of the invention, and reference is therefore to be had to the appended claims for a definition of the limits of the invention.

What is claimed is:

1. In combination, an electric motor having a commutator, a supporting member mounted for rotative adjustment around the axis of said commutator, a plurality of arms mounted on said supporting member, brushes carried by said arms normally out of engagement with said commutator, and means for flexing said arms to displace said brushes into engagement with said commutator.

2. In a device of the class described, the combination of a rotatable shaft, a relatively'light disc mounted on said shaft for rotation therewith, a relatively heavy armature comprising axially aligned annular laminations secured to said disc in sufficient number to constitute an inertia member of substantial weight and length, polar projections fixedly mounted around said shaft but within both the radial and axial limits of said armatures, and a commutator mounted on said shaft beyond the axial limits of said armature.

3. In a device of the class described, the combination of a rotatable shaft, a relatively heavy armature of annular formation and substantial extent axially of said shaft, said armature constituting an inertia member rotatable with said shaft and polar projections fixedly mounted around said shaft but within both the radial and axial limits of said armature, a commutator mounted on said shaft beyond the axial limits of said polar projections, brushes for said commutator, and means for swinging said brushes about parallel axes to engage and energize said commutator.

4. In a device of the class described, the combination of a casing having a cup-shaped part M one end thereof, a rotatable shaft within said casing, said shaft being adapted to be connected to a member to be driven, a disc mounted on said shaft for rotation therewith, a commutator also mounted on said shaft and extending within said cup shaped part, a relatively heavy armature of annular formation and substantial radius mounted on said disc, said armature constituting an inertia member, means including polar projections disposed within said armature and secured to said casing, commutator engaging brushes extending through said cup-shaped part and axially spaced from said polar projections, and axially extending current conducting means disposed between said shaft and polar projections to connect said brushes and armature.

5. In a device of the class described, the combination of a casing, a rotatable shaft within said casing, said shaft being adapted to be connected to a member to be driven, a disc mounted on said shaft for rotation therewith, said disc having a hub drivably connected to said shaft, 9. commutator mounted on said shaft, a. relatively heavy armature of annular formation and substantial radius mounted on said disc and surroundng said hub, said armature constituting an inertia member, means including polar projections surrounding said hub and disposed within said armature and axially extending current conducting means disposed between said shaft and polar projections to electrically connect said commutator and armature.

III

6. In combination, an electric motor having a commutator, a housing around said commutator, a part mounted on said housing for rotative adjustment around the commutator axis, a pair of cantilever springs carried by said part, a commutator brush associated with each spring, and means engageable with the free end of each of said springs to move said brushes into engagement with said commutator.

7. In combination, an electric motor having a commutator, a housing around said commutator, means mounted on said housing for rotative adjustment around the commutator axis, a pair of cantilever springs carried by said adjustable means, a commutator brush associated with each spring, means for moving said brushes into engagement with said commutator, said last named means comprising a member bridging the free ends of said springs, and manually operable means for moving said bridging member toward said commutator axis.

8. In a device of the class described, the combination of a casing having a cup-shaped part at one end thereof, a rotatable shaft within said casing, a commutator mounted on said shaft and extending within said cup-shaped part, a relatively heavy armature of annular formation and substantial radius surrounding said shaft, said armature constituting an inertia member rotatable with said shaft, means including polar projections disposed within said armature and secured to said casing, and axially extending current conducting means disposed between said shaft and polar projections to connect said commutator and armature.

ROLAND CHILTON.

III 

